Creating a Stack using Linked List.


The operations to be supported:

1. PUSH

2. POP

3. Check if Empty

4. Check if Full

//I have just created the skeleton. Exception handling is not put in yet.

#include
using namespace std;

class stack
{
    public:
        stack();
        ~stack();
        void Push(int inData);
        int Pop();
        void display();
        bool IsEmpty();
    protected:
        typedef struct nodeT
        {
            int data;
            struct nodeT *next;   
        }node;
        node *firstElement;
};

//Class method implementation now
stack::stack()
{
    firstElement = NULL;
    return;
}

stack::~stack()
{
    node *next;
    while(firstElement)
    {
        next=firstElement->next;
        delete firstElement;
        firstElement=firstElement->next;
    }
    return;
}

void stack::Push(int inData)
{
    node *newNode = new node;
    newNode->data=inData;
    newNode->next=firstElement;
    firstElement = newNode;
    return;   
}

//Note that the Pop operation is intended to return the data stored in the top most node and free

//that space in the stack
int stack::Pop()
{
    node *nodeToPop;
    int data;
    nodeToPop=firstElement;
    firstElement=firstElement->next;
    data=nodeToPop->data;
    delete nodeToPop;
    return data;
}

bool stack::IsEmpty()
{
    if(!firstElement) return 1;
    else return 0;
}

void stack::display()
{
    node *ptr;
    ptr=firstElement;
    if(ptr)
    {
        cout<<"The stack elements are: "<<endl;
        while(ptr)
        {
            cout<data<<endl;
            ptr=ptr->next;
        }   
    }
    else
    {
        cout<<"There are no elements in the stack!!!!"<<endl;
    }
}

void main()
{
    stack objStack;
    int indata=0, choice=1;
    while(choice!=0)
    {
        cout<<"Stack Operations Main Menu: 1.Push 2.Pop    3.IsEmpty 4.IsFull 0.Exit"        

<<endl;
        cin>>choice;
        switch(choice)
        {
            case 0:
                exit(1); //Normal program Termination
            case 1:
                cout<<"Enter the number to Push: ";   
                cin>>indata;
                objStack.Push(indata);
                break;
            case 2:
                if(!objStack.IsEmpty())
                {
                cout<<"The number popped from the stack is: "<<objStack.Pop()       

            <<endl;
                }
                else {cout<<"Cannot pop from an empty stack!!!"<<endl;}
                break;
            case 3:
                cout<<"Checking if the stack is empty…";
                if(objStack.IsEmpty())
                {
                    cout<<"The stack is empty."<<endl;
                }
                else
                {
                    cout<<"The stack is not empty"<<endl;;
                }
                break;
            case 4:
                //TO Do
            default:
                cout<<"Illegal Action. Please try again!!!"<<endl;
        }
        objStack.display();
        cin.get();
    }   
}

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s